Don't fret, Zelena (Rebecca Mader) is still alive on Once Upon a Time.

The wicked witch lost one of the most important things to her though — her magic. Regina's (Lana Parrilla) long-lost sister gave up all of her power in Sunday's episode in order to give the heroes the ground they desperately needed to give Emma (Jennifer Morrison) a fighting chance against the Black Fairy (Jaime Murray).

Zelena had never fully ditched the chip on her shoulder from being given up at birth and the Black Fairy knew just how to play the former ruler of Oz. The Black Fairy led Zelena down into the dwarf mines and antagonized her into a fight, which allowed the fairy to use the wicked witch's dark magic to transform the light magic fairy crystals into a weapon of dark magic destruction. Thanks to Zelena's ego, the Black Fairy acquired a magical nuke on the eve of the Final Battle.

Rebecca Mader, <em>Once Upon a Time</em>Rebecca Mader, Once Upon a Time

If Zelena hadn't learned anything from the encounter she might have taken Regina's harsh advice and returned back to Oz and left the heroes with absolutely no hope in countering the Black Fairy's power. Instead, Zelena was able to see what she had done wrong and was willing to swallow her pride to make things right. If her magic was powering the Black Fairy's Final Battle weapon, then her magic could be the thing to stop it.

In an extremely rare instance of selflessness, Zelena destroyed her magic and effectively set the Black Fairy back at square one in her mission to destroy all light magic. This is the first time since Gideon (Giles Matthey) arrived in Storybrooke that the heroes have managed to get an upper hand on the Black Fairy, and it couldn't come at a more opportune time.

Once Upon a Time Reveals Gideon's Heart-Wrenching Backstory

There are only three episodes left in the sixth season of Once Upon a Time, meaning only two more hours until the Final Battle and the final chapter of the story book are revealed. Emma and her team still haven't figured out a surefire to defeat the Black Fairy. After seeing how the Black Fairy was able to whip Zelena and Regina — two of the most powerful sorceresses in any of the realms — around, Emma is going to need a weapon of epic proportions if she wants to destroy the source of all darkness.

There are still a couple of moves left in this game of magical chess, but both sides are going to have to play at the top of their games if they want to make it through to the end of the story. Right now the heroes have the momentum, but they've also lost a great source of magic and it still remains to be seen which side of things Rumple (Robert Carlyle) will align himself with when the time comes.

Here's to the heroes keeping up their good work and making it through the Final Battle.

Once Upon a Time continues Sundays at 8/7c on ABC.